


Ghost Hunters In Green

by JunJoestar



Category: Luigi's Mansion (2001), Luigi's Mansion: Dark Moon, Mario & Luigi RPG (Video Games), Overwatch (Video Game), Super Mario & Related Fandoms
Genre: Crossover, Fun, Gen, Ghosts, Light-Hearted, Paranormal, Supernatural Elements
Language: English
Status: Completed
Published: 2017-04-18
Updated: 2017-08-24
Packaged: 2018-10-20 10:56:18
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 8
Words: 3,612
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10661133
Author URL: https://archiveofourown.org/users/JunJoestar/pseuds/JunJoestar
Summary: Two brothers shoved from the spotlight will have to come together if they wish to save their more appreciated siblings from legions of ghosts, ghouls, and other horrifying and supernatural creatures!





	1. Chapter 1

The crescent moon shone through the clouds over the Mushroom Kingdom on an unforgettable Booween Eve. All throughout the kingdom, little ones donned costumes of their heroes and visited homes, asking for treats or coins from adults, lest the ominous King Boo bring a nasty trick down on the household! Of course, Luigi, despite his immense fear of spooky ghosts, relished the night, as it brought him pride to see the occasional child dressed as him instead of his big brother. Comments like 'You're so brave, Luigi! I wanna be just like you!', or 'Wow, Luigi! You're pretty good at sports and kart racing which pretty cool!' made his night, and for that reason, he always sat out on his porch with the best treats. He rocked in his hand-made chair, eagerly awaiting the legions of costumed kids.

The same crescent moon barely illuminated the waiting room Genji sat in, awaiting Doctor Ziegler. Genji had not much been one for Halloween celebrations, but he appreciated the joy they brought others, and it was meaningful to see children inspired by his work. This Halloween night, however, was not an occasion where he had even a moment to sit and think about little ones in costumes or candy or the Monster Mash. After sustaining a serious injury to his relatively fresh cybernetics in training, he sat in relative agony waiting for treatment. Power had gone out at the Swiss headquarters due to the up and coming hacker Sombra, and as such Mercy was far behind on her patients, having to work in such low light. She took a brief pause from her current patient to give Genji an update. "I'm sorry, Genji. It's going to be another hour or so," she said. "How is the pain?" He sighed and shrugged. "I..need healing. But I will be fine for now."


	2. Chapter 2

The first Trick or Treat-er approached Luigi's porch. He stood up and waved, and went to grab the bowl of treats he had at the ready. "Just-a minute!" he yelled. He searched all over the porch, on all his patio furniture, and yet he couldn't find the bowl! "Gee, mister. I guess you want a trick instead, huh?" asked the child, impatiently. Luigi's mustache fluttered with fright at the thought of Boos descending on his house as the result of a Booween Eve trick! "N-n-no! I gotta treats...uhhh...here-a you go!" Luigi panicked and gave the child all the coins he had in his pockets. "Wow, thanks! I can finally get a Attack FX Z badge!" the child giggled and scurried off. Luigi went inside to find Mario to make an emergency treat run to avoid any further incidents. But Mario was nowhere to be found either! "Maaaario! Mario? Ma-a-aarioooo!"

Genji dozed off to pass the time waiting for Mercy. His peaceful slumber was quickly interrupted by horrible nightmares. A monstrous deformed red dragon made of light swirled around him, screaming and bellowing. "BROTHER! You have cursed me to this fate," shouted the dragon. Genji was confused. It was his brother who had forced him into this cybernetic frame, and he who escaped such a terrible fate. "Hanzo, I have not done this to you. You are responsible for your own life, now." The dragon's harsh movements ceased and he stared into Genji's eyes. "You do not understand, brother. In due time you will have to free me from this curse." With that, Genji awoke, startled and unable to ask his brother for more information.


	3. Chapter 3

Luigi searched frantically everywhere around the brothers' home but Mario was nowhere to be found. He quickly locked up and scurried into town to see if the Princess had any idea where he might be, but upon reaching Toad Town, foot traffic had reached a standstill. Kids and parents were lining up for blocks to get to the entrance of Peach's Castle to receive the most luxurious treats in the land from the Princess herself. Unfortunately for Luigi, the amount of costumes meant he had no easy way of proving he was really Luigi since the vast majority of the royal guard Toads confuse him for being Green Mario even on regular days. So Luigi did the one thing any slender green plumber can- tucked himself up in a ball, charged power, and unleashed a maxed out Luigi Torpedo over the entire crowd, sticking the landing by slamming his face directly into the stained glass window over the castle doors. The crowd was struck with awe and surprise and shock, and Luigi slowly slopped down the window, like a pile of slime he plumbed from a clogged pipe, before landing on the ground, right on his dainty behind. The Princess laughed and rushed over, with Toadsworth at her side struggling to keep up. "Oh, Luigi! You're such a card!" she chuckled at him again as he stood up, nursing his now bruised bottom. "What's got you in such a fuss?"  
Luigi adjusted his cap and mustache before bowing to the Princess. "I'm-a sorry to bother you, but have you seen Mario anywhere?" Peach pondered for a moment, and Toadsworth checked his itinerary to see if Mario had been in at all today. "I'm sorry, Luigi. I haven't seen him either. Is something wrong?" said the Princess, starting to get concerned with the situation. "Well, all I can-a say is _Mario is Missing!_ ," said Luigi. somewhere off in the crowd, a Goomba in a Geno costume groaned at this remark.

Luigi set off back home with haste. He knew that on Booween Eve, if Mario is missing, there's only one sure culprit: the prince of poltergeists, the chancellor of the creepy, the grand master of ghouls, King Boo! Surely the monstrous King Boo had kidnapped his brother once again, although hopefully this time Mario hadn't fallen for something as stupid as a mail-in mansion sweepstakes. As Luigi ran back to grab his trusty Poltergust 3000 and set out for Mario, he did not notice the large downed tree on his path. He fell face first over it and into a dark, seemingly endless hole.

Doctor Ziegler came out into the waiting room. "I hope you got some good rest, Genji. I'm ready to see you now." Genji stood up carefully and limped over to the examining table. He laid down and Mercy began running some diagnostics on his human body while Torbjörn inspected his armor and robotic bits. "What do they have ya doin' down there in training that makes ya end up like this?! This armor wasn't easy to make, you know!" Torbjörn muttered under his breath. "His vitals look alright, you should be fine with some rest, Genji. What happened?" asked Mercy. Genji tried to recall. "The lights went out....and...then I blacked out. I think I heard a sniper shot but...if a sniper had hit my head, I wouldn't be here now, would I, doctor?" Genji said nervously. Mercy checked Genji's mask for signs of bullet impact, and saw nothing. She noticed a slight indentation in the sword at his side. "You're very lucky, Genji. If you had not been deflecting attacks for your training, it likely would have penetrated your armor fully. You might not be sitting here right now!" Genji breathed a sigh of relief. "I still feel unwell. Can you give me anything, Doctor?" Mercy whispered to Torbjörn, and they both looked at each other apprehensively. She coughed, and Torbjörn begrudgingly spoke up. "Genji, you, uh...how can I say this to ya...yer at full health, Genji! You don't need healing! I can give ya an armor pack but that's all." Genji laughed and thanked them, and went off. Mercy and Torbjörn both held their faces in their hands and sighed, hoping that someday Genji might understand battlefield healing protocol.

As Genji set off out of the waiting room and back to training, he pondered the dream he had while in the room. Was Hanzo really trying to reach him, or was this just a manifestation of his guilt? An intrusive thought? A consequence of trying the rich and decadent currywurst meal Reinhardt had prepared earlier? While deep in thought, Genji was not attentive of his surroundings, and he tripped over a supply shelf in the hallway. Instead of hitting the floor tiles, though, he fell into a cartoonishly dark and infinite hole.


	4. Chapter 4

Luigi stood up, and shook himself alert. What just happened? He glanced around, but the space he was in was far too dark to see anything. Luigi was seriously worried he wouldn't be able to get out of this jam! He didn't even know how far he'd fallen or really, when he had stopped falling. He didn't remember hitting the ground at all, actually, but at some point, he no longer felt the rush of air and assumed he was on the ground. He felt around his overalls searching for his Game Boy Horror, which would provide a little illumination. He switched it on and started carefully looking for any sort of wall, but the darkness seemed to extend forever. He kept his light on the ground instead, then, hoping he might find anything useful as he walked along. Suddenly, he heard a loud clang and felt an immense pain shoot up his whole leg! Ya-owowowow! What did he kick? He shone the light and gasped with shock to discover a metallic man lying on the ground!

Genji stirred when he felt something bump against his leg. He sat up carefully, fearful it may be some creature here to attack or devour him. He slowly put his hand to his sword's hilt and prepared to draw, before he saw what it was in his optics. "Excuse me...Are you alright? You look to be in extreme pain." Luigi yelped again. "Mama mia! You can-a talk!?"

**Notes for the Chapter:**

> There will be a brief hiatus over the weekend as I will be attending C2E2. Normally my goal is to write a chapter a day, I realize I missed one this week; however, since Chapter 3 was much longer than the first 2 I figured that would be acceptable.


	5. Chapter 5

Luigi and Genji walked along the dark and seemingly endless passage, sharing their stories with each other. They realized they had more in common than a cyborg ninja and a cartoonishly proportioned plumber would seem to. Both green, both taller than their brother, and both constantly in the shadow of this brother. The two also perfected some new Bros. Style techniques with each other that would hopefully allow them to complete this adventure even quicker. But they were still stuck in what seemed to be an infinite black underground cavern. The duo stopped walking for a while and sat to ponder their options. Suddenly, Luigi's Gameboy Horror buzzed and a familiar jingle played! He nearly dropped it in his excitement to pick it up and read the text from Professor E. Gadd.

-Luigi!   
-I hope this message reaches you well.   
-My scanners indicate you're trapped in a liminal space between worlds right now.  
-I've been working on a device in my spare time that should help you out!  
-Watch your head!

Watch your head? Luigi scratched his nose and continued readi-  
BOINK!

One of Gadd's gadget crates fell from the endless sky onto Luigi's head, and bounced to the ground next to him. The crate popped open, and a new piece of tech was inside!

-This is my latest creation: The NintenBOO DS XLuigi!  
-There's an option on it that should allow you to access other worlds.  
-Good luck!  
-E. Gadd

Luigi put the Gameboy Horror back into his overall pocket, and booted up the new device. The backlight screen displayed a calendar, clock, and several settings and options menus. The button to select the current cartridge indicated WorldSwapDelux was the active game. Luigi tapped it with the stylus as Genji watched over his shoulder.   
"This is a most interesting item, Luigi. Does this professor always make such whimsical gadgets?" Genji asked. Luigi nodded, absorbed into the system. He looked around at the infinite selection of worlds, trying to find the Mushroom Kingdom. He nearly selected it before Genji abruptly put his hand on his shoulder and stopped him. "Wait! Do not go back yet. I saw something there that reminded me of...a nightmare I had. Can we please check it? It would be very important to me." Luigi understood his new friend, so he selected the unlabeled world with a distorted image of a screaming dragon. At first, nothing occured. Luigi tapped the button furiously. After some time, the screen shot out beams of red light, and the two were sucked in!


	6. Chapter 6

The two found themselves in a confusing new world. Trees around them were gnarled and grew away from sunlight. The grass was a dark and unwelcoming teal and the sky was filled with ominous purple clouds. A full moon hung like a foglight in the middle of the sky, illuminating the path in front of them. Lightning cracked all around but there was no rain. They stood at the edge of a cliff, with a path trailing off into the woods guiding them in the only reasonable direction. 

As the two walked along the path, Luigi felt odd presences whipping past him. It felt like the cold rush of a Boo, blustering by, but they were too quick to spot. It had been a long time since he had encountered the legion of Boos that haunted the mansion his brother had been trapped in, but he could never forget how it felt. On the one hand, it was terrifying to do that adventure almost entirely on his own, especially when faced with hordes of ghosts, but it felt nice to be in the spotlight for once. As he became lost in his thoughts, he did not notice that the woods were quickly becoming far less dense. A mansion grew on the horizon. He sighed and realized that he would almost definitely be suiting up to bust some Boos once again.

Genji was not a superstitious man, but he could not deny the evidence in front of him. Spectral images flashed briefly in front of him and his companion as they approached the mansion and the chilling gusts of wind and menacing laughter carried by it were undeniable. He steeled his nerves and prepared for the worst as he and Luigi reached the doors of the mansion. "Are you ready for this, my friend?" he asked. Luigi silently nodded, and the two worked together to open the massive door of the house. It creaked and bellowed, as if no one had touched it a thousand years, and the two stepped inside the menacing building.


	7. Chapter 7

The foyer of the mansion was full of furniture covered with white fabric dust protectors. A thick coat of dust sat on top of every exposed surface, and giant dust particles floated through the air as if they had a mind of their own and places to be. Sometimes these dust orbs seemed to glow with light, but surely it was just a trick of the mind. Genji and Luigi surveyed the room for anything useful or any indication of how to advance. The room had a single plain wooden door, but when Luigi jiggled the handle he could feel that it was tightly locked. He sat on one of the covered sofas to think for a moment. Suddenly, he rose with a start! A loud buzzing noise could be heard from in his overalls, so he stopped panicking and realized it was another message from E. Gadd. This one didn't have any words, but contained a file called polter.exe. Luigi opened the file, and suddenly the Gameboy Horror startled to rumble and become very warm. Yowch! Luigi instinctively dropped the Gameboy to the ground as it became superheated. It began glowing as it became white hot, and after a few seconds, a fully functional Poltergust 5000 burst from the screen! Luigi strapped it on to his back and returned to the Gameboy Horror to his pocket. Now he was in business! He motioned for Genji to sit back and watch as he set out to what he did best: vacuuming! Luigi's new gear had such great suction power that it ate up the dust covers almost instantly, and made quick work of all the dust in the room. As he cleaned and searched for a key, he did not notice the glowing dust particles gradually collecting and forming into a great orb behind him. Genji screamed out to him. "Luigi! Turn around, quickly!" Unfortunately, it was too late. Luigi turned around to see the gaping maw of an Atomic Boo laughing and slobbering in his face! He was quickly coated in ectoplasmic saliva, and shook with fear. "M-m-m-m-maaamaaa!!!" He bellowed, before falling flat on his butt and accidentally bumping the Turbo Drive switch on the Poltergust as he fell. The machine worked with immense strength and the Atomic Boo could barely manage to struggle out of its grasp! The giant Boo shrieked and wailed as its body became smaller and smaller as the vacuum sucked in its form. In just a few moments, the ghost was totally gone, and a rusty key dropped to the floor where it once floated. Genji helped Luigi up and handed him the key. "Good job, my friend. You performed with great bravery." He patted him on the back. LUigi smirked, and they prepared to advance into the next room.


	8. Chapter 8

**Summary for the Chapter:**

> It's been on hiatus and you probably thought I forgot about it but I totally didn't and this was definitely totally planned. Since it's been off so long and it's unlikely I'll have the memory to update it consistently, I hope this wrap-up pleases anyone who was waiting around for more chapters!

In the next chamber, the two were stunned to find what appeared to be an entire Southwestern desert landscape. It was familiar to Genji, as he felt he'd engaged in combat in this place before, and that there was probably a payload nearby for him to ignore and demand healing while standing in some far off corner. Luigi had never seen such a beautiful landscape; the stacked rock formations in every shade of red and orange amazed him, the cliff faces exposing years of geologic development awed him as well. After a few moments of staring out at things, the situation became bleak, as the sky quickly darkened and fierce bolts of lightning flashed across the expanse. A ghostly and menacing laugh could be heard nearby. Genji recognized the sound of the harsh and brooding individual as none other than Gabriel Reyes. Genji readied his blade, expecting a fight from the former Blackwatch operative, but instead, Reaper appeared in front of the two, and offered his assistance. "Looks like you've flown too far from home, Sparrow..." Genji scoffed, but the three descended from the mesa they were on and walked towards the payload. Suddenly a bullet whizzed past Luigi's head, and another pierced his emblem on his hat. "Sniper! Get down!" Reaper shouted, assuming his ghost form to teleport to the sniper's post. Amelie didn't notice him phase, and aimed again at Luigi, her red dot right between his eyes. "Au revoir, haricot vert..." She fired, but the shot glanced off the ground in front of him, as Reaper knocked the rifle down out of her arms as she pulled the trigger. The two engaged in melee combat for a bit, as Genji climbed and jumped his way up the scaffolding to reach them. He leaped over Reaper's head and sliced down, assuming he had killed the sniper. Instead, Widowmaker faded into a cloud of pink ghost-like goo, and the familiar laugh of a Boo was heard. The stormclouds overhead began to swirl and form a vortex, turning purple and flashing with blue lightning. King Boo himself descended from the vortex, with Widowmaker standing atop his crown. They laughed at the assembled heroes, and behind the king, a cage descended, with Mario and Hanzo trapped inside! Reaper tried to phase up onto King Boo to fight Widowmaker once again, but the giant ghost predicted his movements, and slurped him up with his long prehensile tongue. Luigi was incredibly frightened, but he knew he still had Genji by his side to help him finish the fight. In predictable boss fight fashion, King Boo used his magic to create flying rock platforms leading up to the top of his head. Widowmaker shot down this gauntlet, but Genji continually deflected her shots as he and Luigi deftly outmaneuvered forward. Once on top of the ghost, King Boo seemed to abandon his teammate, leaving her with no more support in her fight against the two green men. Between Luigi's powerful side-B and Genji's Dragonblade, she met her match. Rather than let herself taste Genji's blade, though, she used her hook and grappled off the world, never to be seen or heard from again (at least, not in this world.) Now it was time to fight the big Boo himself! Luigi tipped his cap and steeled his nerves. Genji again used his deflection to help Luigi, deflecting King Boo's tongue as Luigi used his Poltergust to slowly suck up chunks of the giant ghost. As his size dwindled, Reaper became free, and set forth to the cage to free Hanzo and Mario. King Boo became even smaller, and once he was about the size of a grapefruit, Luigi relented. King Boo began sobbing and whining uncontrollably. "This is no fair! I was supposed to win this time! You rotten brothers are always beating me!" Luigi simply chuckled, and sucked up what little remained of King Boo. His crown dropped before them, and Luigi tucked it away, knowing it would be worth a hefty amount of points later on. Reaper finished picking open the cage, and Luigi and Genji were reunited with their brothers. Using the power of E Gadd's inventions combined, everyone bid a fond farewell and returned to their respective homeworlds. It was a night none of them would ever forget, particularly Luigi and Genji, who often remembered each other fondly, for their power combined let them both unlock their truer selves.


End file.
